OpenAPI Copy by GusevP

Copy one endpoint out of an OpenAPI spec — with every schema it references — and
paste it straight into a chat with an LLM.

A full spec is 100–500 KB and eats an assistant's whole context window. Cutting out
the part you need by hand is not an option either: in Swagger UI the schema is
rendered as a tree of divs, so copying from the page gives you text, not a spec.
OpenAPI Copy gives you a self-contained OpenAPI document, usually 1–3 KB.

How it works

1. Open a Swagger UI page and click the toolbar icon. Nothing is requested at
   install time — the extension reads the page only after that click.
2. Use the Copy button that appears next to each operation, or pick endpoints from
   the popup list.
3. Paste. The output is a valid OpenAPI document, in YAML or JSON.

What you get

• Four modes: the whole endpoint, only its request body, only the 2xx response, or
the entire spec.
• Every $ref resolved inside the copied document. Components are collected
transitively, so recursive schemas (Comment.replies: [Comment]) and allOf branches
survive intact.
• Security schemes included in every mode — they are not reachable through $ref, and
without them an assistant does not know about your auth header.
• A filter and multi-select in the popup, for grabbing several endpoints at once.
• Swagger 2.0 as well as OpenAPI 3: definitions, securityDefinitions and body
parameters are handled by the same code path.
• Bare spec files work too — open openapi.json or /api-docs directly and the popup
parses the page itself.
• A manual URL field for pages that carry no spec of their own.

Permissions

The extension asks for nothing at install time. It reads a page only after you click
the icon, and it requests access to a site only when you turn on "Always on this
site" for that site — switching it back off drops both the registration and the
permission.

Nothing is collected and nothing is sent anywhere. The spec never leaves your
browser; the only thing stored is your YAML/JSON preference.

Limitations

• In-page buttons are built for Swagger UI. On other renderers the popup still works,
there are simply no buttons in the page.
• A spec inlined into the HTML is not detected — only specs the page loaded as a
separate request, plus the page itself.
• The request-body and response modes drop fields the OpenAPI specification requires.
That output is a fragment meant for an LLM, not a document for a validator.

Source code: https://github.com/GusevP/openapi-copy-extension (MIT)